RDMA/hns: Fix error during modify qp RTS2RTS

One qp state migrations legal configuration was deleted mistakenly.

Fixes: 357f3429 ("RDMA/hns: Simplify the state judgment code of qp")
Link: https://lore.kernel.org/r/1595932941-40613-7-git-send-email-liweihang@huawei.com


Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>